Multi-User Medical Robotic System for Collaboration or Training in Minimally Invasive Surgical Procedures

ABSTRACT

A multi-user medical robotic system for collaboration or training in minimally invasive surgical procedures includes first and second master input devices, a first slave robotic mechanism, and at least one processor configured to generate a first slave command for the first slave robotic mechanism by switchably using one or both of a first command indicative of manipulation of the first master input device by a first user and a second command indicative of manipulation of the second master input device by a second user. To facilitate the collaboration or training, both first and second users communicate with each other through an audio system and see the minimally invasive surgery site on first and second displays respectively viewable by the first and second users.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/006,555, filed Jan. 26, 2016, which is a divisional of U.S. patentapplication Ser. No. 13/965,581, filed Aug. 13, 2013, now U.S. Pat. No.9,271,798, which is a divisional of U.S. patent application Ser. No.11/319,012, filed Dec. 27, 2005, now U.S. Pat. No. 8,527,094, whichclaims priority from U.S. Provisional Application No. 60/725,770, filedOct. 12, 2005, which is incorporated herein by this reference.

This application is also a continuation-in-part of U.S. patentapplication Ser. No. 11/025,766, filed Dec. 28, 2004, which is acontinuation of U.S. patent application Ser. No. 10/214,286, filed Aug.6, 2002, now U.S. Pat. No. 6,858,003, which is a divisional of U.S.patent application Ser. No. 09/436,982, filed Nov. 9, 1999, now U.S.Pat. No. 6,468,265, which claims priority from U.S. Provisional PatentApplication No. 60/109,359, filed Nov. 20, 1998, U.S. ProvisionalApplication No. 60/109,301, filed Nov. 20, 1998, U.S. ProvisionalApplication No. 60/109,303, filed Nov. 20, 1998, and U.S. ProvisionalApplication No. 60/150,145, filed Aug. 20, 1999, and which is acontinuation-in-part of U.S. patent application Ser. No. 09/433,120,filed Nov. 3, 1999, now U.S. Pat. No. 6,659,939, which is acontinuation-in-part of U.S. patent application Ser. No. 09/399,457,filed Sep. 17, 1999, now abandoned, which is a continuation-in-part ofU.S. patent application Ser. No. 09/374,643, filed Aug. 16, 1999, nowabandoned, which claims priority from U.S. Provisional PatentApplication No. 60/116,891, filed Jan. 22, 1999, U.S. Provisional PatentApplication No. 60/116,842, filed Jan. 22, 1999, and U.S. ProvisionalPatent Application No. 60/109,359, filed Nov. 20, 1998, all of which areincorporated herein by this reference.

This application is also a continuation-in-part application of U.S.patent application Ser. No. 10/948,853, filed Sep. 23, 2004, now U.S.Pat. No. 7,413,565, which is a divisional of U.S. patent applicationSer. No. 10/246,236, filed Sep. 17, 2002, now U.S. Pat. No. 6,951,535,which is a continuation of U.S. patent application Ser. No. 10/051,796,filed Jan. 16, 2002, now U.S. Pat. No. 6,852,107, all of which areincorporated herein by this reference.

FIELD OF THE INVENTION

The present invention generally relates to minimally invasive roboticsurgery systems and in particular, to a multi-user medical roboticsystem for collaboration or training in minimally invasive surgicalprocedures.

BACKGROUND OF THE INVENTION

While clinical growth of laparoscopic procedures has stalled,tele-operated robotic surgical systems have been successful in achievinggreater procedure development and clinical acceptance in severalsurgical fields. Two examples of such surgical robotic systems includethe da Vinci® Surgical System of Intuitive Surgical, Inc., Sunnyvale,Calif., and the Aesop® and Zeus® robot systems of Computer Motion, Inc.,which has been acquired by Intuitive Surgical, Inc.

For example, the da Vinci® surgical system can be used for a widevariety of surgical procedures such as mitral valve repair, NissenFundoplication for the treatment of GERD disease, gastric bypass surgeryfor obesity, radical prostatectomy (da Vinci® Prostatectomy) for theremoval of the prostate, esophageal surgery, thymectomy for myastheniagravis, and epicardial pacemaker leads for biVentricularresynchronization.

Minimally invasive surgery offers many benefits over traditional opensurgery techniques, including less pain, shorter hospital stays, quickerreturn to normal activities, minimal scarring, reduced recovery time,and less injury to tissue. Consequently, demand for minimally invasivesurgery is strong and growing.

Since robotic minimally invasive surgery (“RMIS”) is still a nascentfield, however, there are no commercially available training systemsthat allow a trainee and mentor to experience the same environment, andphysically interact as they would in open or even conventionallaparoscopic surgery training. Instead, current RMIS training consistsof training courses explaining the robotic device and surgical techniqueaccompanied by laboratory practice in animal and cadaver models,followed by watching already proficient surgeons perform the procedure.A proficient surgeon then assists/supervises the newly trained surgeonduring his or her initial procedures.

In a tele-robotic paradigm, this mentoring problem can be generalizedirrespective of the location of the two surgeons. However, when they arecollocated, the ability to view the surgical scene together, combinedwith the ability to exchange or share control of the instruments canenable physical interaction between the trainee and the mentor, andprovide a superior training environment.

OBJECTS AND SUMMARY OF THE INVENTION

Thus, a multi-user medical robotic system which allows a mentor surgeonto communicate with trainee surgeons, to see the same surgical site asthe trainee surgeons, to share control of robotically controlledsurgical instruments with the trainee surgeons so that they may feelthrough their controls what the mentor surgeon is doing with his/hers,and to switch control to selected ones of the trainee surgeons andover-ride that control if necessary during the performance of aminimally invasive surgical procedure, would be highly beneficial fortraining purposes.

In addition, such a multi-user medical robotic system would also beuseful for collaborative surgery in which multiple surgeons worktogether as a team (i.e., in collaboration) to perform a minimallyinvasive surgical procedure.

Accordingly, one object of the present invention is to provide amulti-user medical robotic system that facilitates collaboration betweensurgeons while performing minimally invasive surgical procedures.

Another object is to provide a multi-user medical robotic system thatfacilitates training of surgeons to perform minimally invasive surgicalprocedures.

These and additional objects are accomplished by the various aspects ofthe present invention, wherein briefly stated, one aspect is a medicalrobotic system comprising: first master input device configured togenerate a first command indicative of manipulation of the first masterinput device by a first user; second master input device configured togenerate a second command indicative of manipulation of the secondmaster input device by a second user; first slave robotic mechanismconfigured to manipulate a first surgery-related device according to afirst slave command; at least one processor configured to generate thefirst slave command by switchably using one or both of the first commandand the second command; and an audio system configured for audiocommunication between the first user and the second user.

Another aspect is a multi-user medical robotic system for collaborationin minimally invasive surgical procedures, comprising: first and secondmaster input devices; first and second slave robotic mechanisms; aswitch mechanism operable by a first operator for selectivelyassociating the first and the second slave robotic mechanisms with thefirst and the second master input devices so that the first operatormanipulating the first master input device and a second operatormanipulating the second master input device may perform a minimallyinvasive surgical procedure at a surgical site in collaboration witheach other; and first and second headsets respectively worn by the firstand the second operators so that they may communicate with each whileperforming the minimally invasive surgical procedure in collaborationwith each other.

Another aspect is a multi-user medical robotic system for training inminimally invasive surgical procedures, comprising: mentor and traineemaster input devices respectively manipulatable by a mentor and atrainee; a first slave robotic mechanism; a switch mechanism operable bythe mentor for selectively associating the first slave robotic mechanismwith the mentor master input device and the trainee master input deviceso that either or both the mentor or the trainee may control operationof the first slave robotic mechanism to perform a minimally invasivesurgical procedure; and a mentor microphone proximate to the mentor anda trainee hearing device proximate to the trainee so that the mentor mayspeak to the trainee while the mentor is performing the minimallyinvasive surgical procedure.

Additional objects, features and advantages of the various aspects ofthe present invention will become apparent from the followingdescription of its preferred embodiment, which description should betaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a top view of a multi-user medical robotic system forcollaboration or training in minimally invasive surgical procedures,utilizing aspects of the present invention.

FIGS. 2-3 illustrate simplified front views respectively of mentor andtrainee master control stations configured to utilize aspects of thepresent invention.

FIG. 4 illustrates a block diagram of a master/slave control systemincluded in the multi-user medical robotic system, utilizing aspects ofthe present invention.

FIGS. 5-9 illustrate block diagrams of selected master/slaveassociations for a multi-user medical robotic system, utilizing aspectsof the present invention.

FIG. 10 illustrates a block diagram of components of the multi-usermedical robotic system for selective association of masters and slaves,utilizing aspects of the present invention.

FIG. 11 illustrates an example of input/output ports for an associationmodule, utilizing aspects of the present invention.

FIGS. 12 and 13 illustrate routing tables corresponding to themaster/slave associations of FIGS. 9 and 8, respectively, of anassociation module utilizing aspects of the present invention.

FIGS. 14 and 15 illustrate block diagrams for alternative embodiments ofa shared command filter of an association module, utilizing aspects ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates, as an example, a multi-user medical robotic system100 useful for collaboration or training in minimally invasive surgicalprocedures. For example, in a collaborative operation, a team of two ormore proficient surgeons may work together to perform a minimallyinvasive surgical procedure, or an expert surgeon may advise a primarysurgeon performing a minimally invasive surgical procedure. In ahands-on training environment, a mentor surgeon may act as a mentor orteacher to train one or more trainee surgeons in minimally invasivesurgical procedures.

Although configured in this example for a local environment with allparticipants locally present, the multi-user medical robotic system 100may also be configured through a network connection for remoteparticipation by one or more participants. For example, a remote surgeonmay provide guidance or support to a primary surgeon at a localoperating site. In such case, the advising surgeon may share theimmersive audio/video environment with the primary surgeon, and mayaccess the surgical instruments as desired by the primary surgeon.

Although a training example is described herein, the describedcomponents and features of the system 100 are also useful incollaborative surgery. In particular, it is useful for a lead surgeon inthe case of a collaborative procedure to control the selectiveassociation of certain surgical tools and/or an endoscope with any oneof the participating surgeons during a minimally invasive surgicalprocedure, just as it is for a mentor surgeon in the case of a trainingsession to control the selective association of certain surgical toolsand/or an endoscope with any one of the trainee surgeons during aminimally invasive surgical training session. Also, it is useful in boththe collaboration and training environments for all participants to beable to view the surgical site and to communicate with each other duringthe surgical procedure or training session.

In reference to FIG. 1, a Mentor Surgeon (M) instructs or mentors one ormore Trainee Surgeons, such as (T1) and (TK), in minimally invasivesurgical procedures performed on a real-life or dummy Patient (P). Toassist in the surgical procedures, one or more Assistant Surgeons (A)positioned at the Patient (P) site may also participate.

The system 100 includes a mentor master control station 101 operative bythe Mentor Surgeon (M), a slave cart 120 having a plurality of slaverobotic mechanisms (also referred to as “robotic arm assemblies” and“slave manipulators”) 121˜123, and one or more trainee master controlstations, such as trainee master control stations 131 and 161, operativeby Trainee Surgeons, such as Trainee Surgeons (T1) and (TK). The mentormaster control station 101, in this example, communicates directly withthe slave cart 120, and the trainee master control stations communicateindirectly with the slave cart 120 through the mentor master controlstation 101.

The slave cart 120 is positioned alongside the Patient (P) so thatsurgery-related devices (such as 157) included at distal ends of theslave robotic mechanisms 121˜123 may be inserted through incisions (suchas incision 156) in the Patient (P), and manipulated by one or more ofthe participating surgeons at their respective master control stationsto perform a minimally invasive surgical procedure on the Patient (P).Each of the slave robotic mechanisms 121˜123 preferably includeslinkages that are coupled together and manipulated through motorcontrolled joints in a conventional manner.

Although only one slave cart 120 is shown being used in this example,additional slave carts may be used as needed. Also, although three slaverobotic mechanisms 121˜123 are shown on the cart 120, more or less slaverobotic mechanisms may be used per slave cart as needed.

A stereoscopic endoscope is commonly one of the surgery-related devicesincluded at the distal end of one of the slave robotic mechanisms.Others of the surgery-related devices may be various tools withmanipulatable end effectors for performing the minimally invasivesurgical procedures, such as clamps, graspers, scissors, staplers, andneedle holders.

Use of the stereoscopic endoscope allows the generation and display ofreal-time, three-dimensional images of the surgical site. Although thestereoscopic endoscope is preferred for this reason, a monoscopicendoscope may alternatively be used where either three-dimensionalimages are not needed or it is desirable to reduce communicationbandwidth requirements.

Alternatively, the system may include multiple endo scopes providingeach individual surgeon with a desired view of the workspace.Advantageously, the multiple endoscopes may even be packaged in a singleinstrument, but with separate steerable camera tips. Optionally, thesemultiple endoscopes may provide different fields of view such as using avery wide field of view (e.g. with a fish-eye lens) that isappropriately rectified before being displayed to the surgeon.

To facilitate collaboration between surgeons or training of traineesurgeons in minimally invasive surgical procedures, each of theparticipating surgeons has an associated display to view the surgicalsite, and a communication means such as a microphone and earphone set tocommunicate with other participating surgeons.

More particularly, a display 102 is provided with or integrated into thementor master control station 101, a display 132 is provided with orintegrated into the trainee master control station 131, and a display142 is provided on a vision cart 141 which is in view of the one or moreAssistant Surgeons (A), so that the Mentor Surgeon (M), the TraineeSurgeon (T), and the Assistant Surgeon(s) (A) may view the surgical siteduring minimally invasive surgical procedures.

The vision cart 141, in this example, includes stereo camera electronicswhich convert pairs of two-dimensional images received from thestereoscopic endoscope into information for correspondingthree-dimensional images, displays one of the two-dimensional images onthe display 142 of the vision cart 141, and transmits the information ofthe three-dimensional images over a stereo vision channel 111 to themaster control stations of participating surgeons, such as the mentormaster control station 101 and the trainee master control stations, fordisplay on their respective displays. For displaying stereo informationusing properly configured conventional displays, the vision cart 141 maycontain devices for frame synchronization, and in that case,conventional video cables may be sufficient for sharing this informationbetween collocated surgeons.

The communication means provided to each of the participants may includeindividual microphone and earphones (or speaker) components, oralternatively, individual headphone sets, such as headphone set 103shown as being placed on the head of the Mentor Surgeon (M), as part ofa conventional audio system. Preferably a duplex audio communicationsystem (microphone and speaker pair) is built into each surgeon's mastercontrol station. Alternatively, headsets may be used, including thoseusing wireless communications to provide maximum comfort and freedom ofmovement to their users or those that may be connected through wires totheir respective master control stations or slave cart, which are inturn, are connected together through mentor/slave lines 110 andmentor/trainee lines 112 for voice communications between the Mentor,Trainee and Assistant Surgeons.

In addition to transmitting voice communications, the mentor/slave andthe mentor/trainee lines, 110 and 112, also transmit data. For highbandwidth and low latency communication, the lines 110 and 112, as wellas the stereo vision channel lines 111, are preferably composed of fiberoptic communication cables/channels, which are especially useful whenany of the mentor master control station 101, the trainee master controlstations (such as 131 and 161), and the slave cart 120 are remotelysituated from the others. On the other hand, for co-located surgeons,normal shielded video and audio cables may be sufficient, while fiberoptical communication channels may be used for the mentor/slave ormentor/trainee data transfer lines.

FIGS. 2-3 illustrate simplified front views of the mentor master controlstation 101 and the trainee master control station 131. The mentormaster control station 101 includes right and left master input devices,203 and 204, whose manipulations by the Mentor Surgeon (M) are sensed bysensors (not shown) and provided to an associated processor 220 via aninstrumentation bus 210. Similarly, the trainee master control station131 includes right and left master input devices, 303 and 304, whosemanipulations by the Trainee Surgeon (T1) are sensed by sensors (notshown) and provided to an associated processor 320 via aninstrumentation bus 310. Each of the master input devices (also referredto herein as “master manipulators”) may include, for example, any one ormore of a variety of input devices such as joysticks, gloves,trigger-guns, hand-operated controllers, and the like.

The mentor master control station 101 is preferably configured with oneor more switch mechanisms to allow the Mentor Surgeon (M) to selectivelyassociate individual of the slave robotic mechanisms 121-123 with any ofthe master input devices of the mentor master control station 101 andthe trainee master control stations. As one example, two switchmechanisms may be activated by right or left buttons, 205 and 207,positioned on the right and left master input devices, 203 and 204, soas to be manipulatable by right and left thumbs of the Mentor Surgeon(M).

As another example, two switch mechanisms may be activated by right orleft footpedals, 215 and 217, which are positioned so as to bemanipulatable by right and left feet of the Mentor Surgeon (M). Oneswitch mechanism may also be voice activated by the Mentor Surgeon (M)using his headset 103 or another microphone (not shown), which iscoupled to the processor 220 so that it may perform voice recognitionand processing of the spoken instructions of the Mentor Surgeon (M).

For complex associations of various aspects of system master inputdevices and slave robotic mechanisms, a simple binary switch (orcombinations of switches) may not be suitable. In such cases, a moreflexible association selector may be required, such as a menu ofavailable options displayed on the display 102 of the mentor mastercontrol station 101 that the Mentor Surgeon (M) may select from, byusing a conventional pointing device, touch screen, or voice activation.The master input devices or input devices built into the master inputdevices may also be used for this purpose.

To perform a minimally invasive surgical procedure, the operatingsurgeons perform the procedure by manipulating their respective masterinput devices which in turn, causes associated slave robotic mechanismsto manipulate their respective surgery-related devices through minimallyinvasive incisions in the body of the Patient (P) while the surgeonsview the surgical site through their respective displays.

The number of surgery-related devices used at one time and consequently,the number of slave robotic mechanisms in the system 100 will generallydepend on the diagnostic or surgical procedure and the space constraintswithin the operating room among other factors. If it is necessary tochange one or more of the surgery-related devices being used during aprocedure, the Assistant (A) may remove the surgery-related device thatis no longer needed from the distal end of its slave robotic mechanism,and replace it with another surgery-related device from a tray of suchdevices in the operating room. Alternatively, a robotic mechanism may beprovided for the surgeon to execute tool exchanges using his/her masterinput device.

Preferably, the master input devices will be movable in the same degreesof freedom as their associated surgery-related devices to provide theirrespective surgeons with telepresence, or the perception that the masterinput devices are integral with their associated surgery-relateddevices, so that their respective surgeons have a strong sense ofdirectly controlling them. To this end, position, force, and tactilefeedback sensors are preferably employed that transmit position, force,and tactile sensations from the devices (or their respective slaverobotic mechanisms) back to their associated master input devices sothat the operating surgeons may feel such with their hands as theyoperate the master input devices.

To further enhance the telepresence experience, the three-dimensionalimages displayed on the displays of the master control stations areoriented so that their respective surgeons feel that they are actuallylooking directly down onto the operating site. To that end, an image ofthe surgery-related device that is being manipulated by each surgeonappears to be located substantially where the surgeon's hands arelocated even though the observation points (i.e., the endoscope orviewing camera) may not be from the point of view of the image.

FIG. 4 illustrates, as an example, a block diagram of a master/slavecontrol system 400 for an associated master manipulator and slavemanipulator pair. An example of such a master/slave manipulator pair isthe master device input 203 of the mentor master control station 101 andthe slave robotic mechanism 121. Master manipulator inputs andcorresponding slave manipulator outputs are indicated by arrows AB, andslave manipulator inputs and corresponding master manipulator outputs inthe case of feedback are indicated by arrows BA.

Although the master processing unit 420 and slave processing unit 430described herein may be implemented as analog circuitry, preferably theyare implemented digitally using conventional Z-transform techniques forsampled data systems and provided in program code executed by processorsof master control stations associated with the master and slavemanipulators, 404 and 416, as will be described in further detail inreference to FIG. 10.

In the following description, the master manipulator (i.e., master inputdevice) 404 will be referred to as the master and the slave manipulator(i.e., slave robotic mechanism) 416 will be referred to as the slave, tosimplify the description. Also, positions sensed by joint encoders inthe master manipulator as well as those in the slave manipulator arereferred to as “joint space” positions. Furthermore, references topositions and positioned signals may include orientation, location,and/or their associated signals. Similarly, forces and force signals maygenerally include both force and torque in their associated signals.

For ease of explanation, the master/slave control system 400 will bedescribed from an initial condition in which the master is at an initialposition and the slave is at a corresponding initial position. However,in use, the slave tracks the master position in a continuous manner.

Referring to the control system 400, the master is moved from an initialposition to a new position corresponding to a desired position of theend effector (located on the distal end of the slave) as viewed by thesurgeon on his display. Master control movements are input by thesurgeon 402, as indicated by arrow AB1, by applying a force to themaster 404 to cause the master 404 to move from its initial position tothe new position.

As the master 404 is thus manipulated by the surgeon, signals from theencoders on the master 404 are input to a master controller 406 asindicated by arrow AB2. At the master controller 406, the signals areconverted to a joint space position corresponding to the new position ofthe master. The joint space position is then input to a masterkinematics converter 408 as indicated by arrow AB3. The masterkinematics converter 408 then transforms the joint space position intoan equivalent Cartesian space position. This is optionally performed bya kinematics algorithm including a Jacobian transformation matrix,inverse Jacobian, or the like. The equivalent Cartesian space positionis then input to a bilateral controller 410 as indicated by arrow AB4.

Position comparison and force calculation may, in general, be performedusing a forward kinematics algorithm which may include a Jacobianmatrix. The forward kinematics algorithm generally makes use of areference location, which is typically selected as the location of thesurgeon's eyes. Appropriate calibration or appropriately placed sensorson the master control station can provide this reference information.Additionally, the forward kinematics algorithm will generally make useof information concerning the lengths and angular offsets of the linkageof the master. More specifically, the Cartesian position represents, forexample, the distance of the input handle from, and the orientation ofthe input handle relative to, the location of the surgeon's eyes. Hence,the equivalent Cartesian space position is input into bilateralcontroller 410 as indicated by AB4.

In a process similar to the calculations described above, the slaveposition is also generally observed using joint encoders of the slave416. In an exemplary embodiment, joint encoder signals read from theslave 416 are provided to a slave controller 414, as indicated by BA2,which converts the signals to a joint space position corresponding tothe initial position of the slave 416. The joint space position is theninput to a slave kinematics converter 412 as indicated by arrow BA3. Theslave kinematics converter 412 then transforms the joint space positioninto an equivalent Cartesian space position.

In this case, the forward kinematics algorithm used by the slavekinematics converter 412 is preferably provided with the referencedlocation of a tip of a stereoscopic endoscope capturing images of thesurgery site to be viewed on the surgeon display. Additionally, throughthe use of sensors, design specifications, and/or appropriatecalibration, this kinematics algorithm incorporates informationregarding the lengths, offsets, angles, etc., describing the linkagestructure of the slave cart 120, and set-up joints for the slave 416(i.e., joints used to initially position the slave that are subsequentlylocked during the procedure) so that the slave Cartesian positiontransferred to the bilateral controller 410 is measured and/or definedrelative to the tip of the stereoscopic endoscope.

At bilateral controller 410, the new position of the master in Cartesianspace relative to the surgeon's eyes is compared with the initialposition of the tip of the end effector connected at the distal end ofthe slave 416 in Cartesian space relative to the tip of the stereoscopicendoscope.

Advantageously, the comparison of these relative relationships occurringin the bilateral controller 410 can account for differences in scalebetween the master input device space in which the master input device404 is moved as compared with the surgical workspace in which the endeffectors on the distal end of the slave robotic mechanism 416 move.Similarly, the comparison may account for possible fixed offsets, shouldthe initial master and slave positions not correspond.

Since the master has moved to a new position, a comparison by thebilateral controller 410 of its corresponding position in Cartesianspace with the Cartesian space position of the slave corresponding toits initial position yields a deviation and a new slave position inCartesian space. This position is then input to the slave kinematicsconverter 412 as indicated by arrow AB5, which computes the equivalentjoint space position commands.

These commands are then input to the slave controller 414 as indicatedby arrow AB6. Necessary joint torques are computed by the slavecontroller 414 to move the slave to its new position. These computationsare typically performed using a proportional integral derivative(P.I.D.) type controller. The slave controller 414 then computesequivalent motor currents for these joint torque values, and driveselectrical motors on the slave 416 with these currents as indicated byarrow AB7. The slave 416 is then caused to be driven to the new slaveposition which corresponds to the new master position.

The control steps involved in the master/slave control system 400 asexplained above are typically carried out at about 1300 cycles persecond or faster. It will be appreciated that although reference is madeto an initial position and new position of the master, these positionsare typically incremental stages of a master control movement. Thus, theslave is continually tracking incremental new positions of the master.

The master/slave control system 400 also makes provision for forcefeedback. Thus, should the slave 416 (i.e., its end effector) besubjected to an environmental force at the surgical site, e.g., in thecase where the end effector pushes against tissue, or the like, such aforce is fed back to the master 404 so that the surgeon may feel it.Accordingly, when the slave 416 is tracking movement of the master 404as described above and the slave 416 pushes against an object at thesurgical site resulting in an equal pushing force against the slave 416,which urges the slave 416 to move to another position, similar steps asdescribed above in the forward or control path take place in thefeedback path.

The surgical environment is indicated at 418 in FIG. 4. In the casewhere an environmental force is applied on the slave 416, such a forcecauses displacement of the end effector. This displacement is sensed bythe encoders on the slave 416 which generate signals that are input tothe slave controller 414 as indicated by arrow BA2. The slave controller414 computes a position in joint space corresponding to the encodersignals, and provides the position to the slave kinematics converter412, as indicated by arrow BA3.

The slave kinematics converter 412 computes a Cartesian space positioncorresponding to the joint space position, and provides the Cartesianspace position to the bilateral controller 410, as indicated by arrowBA4. The bilateral controller 410 compares the Cartesian space positionof the slave with a Cartesian space position of the master to generate apositional deviation in Cartesian space, and computes a force valuecorresponding to that positional deviation that would be required tomove the master 404 into a position in Cartesian space which correspondswith the slave position in Cartesian space. The force value is thenprovided to the master kinematics converter 408, as indicated by arrowBA5.

The master kinematics converter 408 calculates from the force valuereceived from the bilateral controller 410, corresponding torque valuesfor the joint motors of the master 404. This is typically performed by aJacobian Transpose function in the master kinematics converter 408. Thetorque values are then provided to the master controller 406, asindicated by arrow BA6. The master controller 406, then determinesmaster electric motor currents corresponding to the torque values, anddrives the electric motors on the master 404 with these currents, asindicated by arrow BA7. The master 404 is thus caused to move to aposition corresponding to the slave position.

Although the feedback has been described with respect to a new positionto which the master 404 is being driven to track the slave 416, it is tobe appreciated that the surgeon is gripping the master 404 so that themaster 404 does not necessarily move. The surgeon however feels a forceresulting from feedback torques on the master 404 which he countersbecause he is holding onto the master 404.

In performing collaborative minimally invasive surgical procedures ortraining in such procedures, it is useful at times for the lead ormentor surgeon to selectively associate certain master input deviceswith certain slave robotic mechanisms so that different surgeons maycontrol different surgery-related devices in a collaborative effort orso that selected trainees may practice or experience a minimallyinvasive surgical procedure under the guidance or control of the mentorsurgeon. Some examples of such selective master/slave associations areillustrated in FIGS. 5-9, wherein each master depicted therein includesthe master manipulator 404 and master processing 420 of FIG. 4 and eachslave depicted therein includes the slave manipulator 416 and slaveprocessing 430 of FIG. 4.

In FIG. 5, an exclusive operation master/slave association is shown inwhich master 501 has exclusive control over slave 502 (and its attachedsurgery-related device), and master 511 has exclusive control over slave512 (and its attached surgery-related device). In this configuration,the masters, 501 and 511, may be controlled by the right and left handsof a surgeon while performing a minimally invasive surgical procedure,or they may be controlled by different surgeons in a collaborativeminimally invasive surgical procedure. The master/slave control system400 may be used for each associated master/slave pair so that lines 503and 513 (master to slave direction) correspond to its forward path AB4line and lines 504 and 514 (slave to master direction) correspond to itsfeedback path BA5 line.

In FIG. 6, a unilateral control master/slave association is shown inwhich master 601 has exclusive control over slave 602 (and its attachedsurgery-related device), but input and reflected force (or position)values are provided to the master 611 as well as the master 601. In thisconfiguration, although the master 611 cannot control the slave 602, ittracks the master 601 so that a surgeon holding the master input deviceof master 611 can feel and experience movement of the master inputdevice of master 601 as it is being manipulated by another surgeon.Thus, this sort of configuration may be useful in training surgeons byallowing them to experience the movement of the master input device ofthe master 601 as it is being manipulated by a mentor surgeon during aminimally invasive surgical procedure, while viewing the surgical sitein their respective displays and communicating with the mentor surgeonusing their respective headsets.

In FIG. 7, a modified version of the unilateral control master/slaveassociation is shown. In this configuration, not only does the surgeonholding the master input device of master 711 experience the movement of(and forces exerted against) the master input device of the master 701as it is being manipulated by another surgeon during a minimallyinvasive surgical procedure, the surgeon associated with master 711 canalso “nudge” the master input device of the master 701 by manipulatinghis/her master input device since a force value corresponding to suchnudging is provided back to the master 701, as indicated by the arrow722. This “nudging” master/slave configuration is useful for trainingsurgeons, because it allows a trainee surgeon to practice by performingthe surgical procedure by manipulating the slave 702 (and its attachedsurgery-related device) using the master input device of his/her master701, while the mentor surgeon monitors such manipulation by viewing thesurgical site on his/her display while feeling the movement of thetrainee surgeon's master input device through input and feedback forces,respectively indicated by arrows 721 and 704. If the mentor surgeonthinks that the trainee surgeon should modify his/her operation ofhis/her master input device, the mentor surgeon can nudge the traineesurgeon's master input device accordingly, while at the same time,communicating such recommendation verbally to the trainee surgeon usinga shared audio system through their respective headsets.

In FIG. 8, a unilateral, shared master/slave association, which is avariant of the nudging configuration of FIG. 7, is shown in which either(or both) masters 801 and 811 may control slave 802. In thisconfiguration, not only does the surgeon holding the master input deviceof master 811 experience the movement of (and forces exerted against)the master input device of the master 801 as it is being manipulated byanother surgeon during a minimally invasive surgical procedure, thesurgeon associated with master 811 can also control the slave 802 ifdesired, as indicated by the arrow 813. This “override” master/slaveconfiguration is useful for training surgeons, because it allows atrainee surgeon to practice by performing the surgical procedure bymanipulating the slave 802 (and its attached surgery-related device)using the master input device of his/her master 801, while the mentorsurgeon monitors such manipulation by viewing the surgical site onhis/her display while feeling the movement of the trainee surgeon'smaster input device through input and feedback forces, respectivelyindicated by arrows 821 and 804. If the mentor surgeon finds itnecessary to assume control of the slave 802 to avoid injury to apatient, the mentor surgeon can assert such control accordingly, whileat the same time, communicating that he/she is taking over controlverbally to the trainee surgeon through a shared audio system.

In FIG. 9, a bilateral master/slave association is shown in whichmasters, 901 and 912, and slaves, 902 and 912, all move in tandem,tracking each other's movements. In this configuration, the slave 912(and its attached surgery-related device) may be controlled by a surgeonusing the master 901, while another surgeon experiences its movement byloosely holding the master input device for the other master 911. Theslave 902 in this case is generally non-operative in the sense that itis not directly participating in the minimally invasive surgicalprocedure. In particular, the slave 902 either may not have the distalend of its slave robotic mechanism inserted in the patient so that itsrobotic arm moves, but does not result in any action taking place in thesurgical site, or the slave 902 may only include a computer model of thelinkages, joints, and joint motors of its slave robotic mechanism,rather than the actual slave robotic mechanism.

However, the slave 902 does move in tandem with the slave 912 (inactuality or through simulation) as the surgeon manipulating the masterinput device of the master 901 causes the slave 912 to move, because aforce (or position) value corresponding to such manipulation is providedto the master 911, as indicated by arrow 921, and the master 911controls the slave 902 to move accordingly, as indicated by arrow 913.Any forces asserted against the surgery-related device attached to thedistal end of the slave robotic mechanism of the slave 912 are then fedback to the master input device of the master 911, as indicated by thearrow 914.

Note that the surgeon associated with the master 911 can effectively“nudge” the master 901 by manipulating the master input device of themaster 911. Therefore, the bilateral master/slave association shown inFIG. 9 can also be used in the training of surgeons in a similar manneras the “nudging” and unilateral, shared master/slave associationsrespectively shown in FIGS. 7 and 8.

FIG. 10 illustrates a block diagram of components of the multi-usermedical robotic system for selective association of master manipulators(also referred to as “master input devices”), 404 and 1004, with slavemanipulators (also referred to as “slave robotic mechanisms”), 416 and1016. Although only two master manipulators and two slave manipulatorsare shown in this example, it is to be appreciated that any number ofmaster manipulators may be associated with any number of slavemanipulators in the system, limited only by master control station portavailability, memory capacity, and processing capability/requirements.

The master processing unit 420 includes the master controller 406 andthe master kinematics converter 408 and generally operates as describedin reference to FIG. 4, and the master processing unit 1020 is similarlyconfigured and functionally equivalent to the master processing unit420. The slave processing unit 430 includes the slave controller 414,slave kinematics converter 412, and the bilateral controller 410 andgenerally operates as described in reference to FIG. 4, and the slaveprocessing unit 1030 is similarly configured and functionally equivalentto the slave processing unit 430.

An association module 1001 includes a shared command filter 1002 and arouting table 1003 for selectively associating master manipulators, 404and 1004, with slave manipulators, 416 and 1016. In brief, the routingtable 1003 indicates which inputs are routed to which outputs of theassociation module 1001, and the shared command filter 1002 determineshow shared command of a slave manipulator by two master manipulators ishandled. One or more switch commands 1005 are provided to theassociation module 1001 as a means for a user to alter parameters of theshared command filter 1002 or values in the routing table 1003 so as tochange or switch the selected associations between master and slavemanipulators. The current parameters of the shared command filter 1002and/or values in the routing table 1003 may be indicated to the userusing a plurality of icons on a graphical user interface of an auxiliarydisplay or the user's master control station display, or they may beindicated by a plurality of light-emitting-diodes or other suchindicators on or adjacent to the user's master control station, or theymay be indicated by any other display mechanism.

The switch command(s) 1005 may be generated by any one or combinationof: the user interacting with one or more buttons on the master inputdevices, the user interacting with one or more foot pedals associatedwith the user's master control station, the user providing recognizablevoice commands to a voice recognition (i.e., word recognition) andprocessing system, the user interacting with one or more menus displayedon the user's master control station display, or the user interactingwith any other conventional input mechanism of such sort.

In a preferred embodiment compatible with the multi-user medical roboticsystem of FIG. 1, master processing 420 is performed as executableprogram code on a processor associated with the master control stationof the master manipulator 404, and master processing 1020 is alsoperformed as executable program code on a processor associated with themaster control station of the master manipulator 1004. Both mastercontrol stations in this case may be Trainee master control stations,such as master control stations 131 and 161 of FIG. 1, or one of themaster control stations may be the Mentor master control station 101 andthe other, a Trainee master control station.

The slave processing 430, the slave processing 1030, and the associationmodule 1001 are preferably included as executable program or table codeon the processor 220 associated with the Mentor master control station101. The switch command(s) 1005 in this case originate from action takenby the Mentor Surgeon (M) operating the Mentor master control station101.

The Mentor master control station 101 preferably performs the slaveprocessing for all slave robotic mechanisms 121˜123, because itcommunicates directly with the slave robotic mechanisms 121˜123, whereasthe Trainee master control stations only communicate indirectly with theslave robotic mechanisms 121˜123 through the Mentor master controlstation 101. On the other hand, the Trainee master control stationspreferably perform the master processing for their respective masterinput devices, so that such processing may be performed in parallel withthe slave processing (while maintaining time synchronization) whileoff-loading these processing requirements from the processor of theMentor master control station 101. Thus, this distribution of processingmakes efficient use of processor resources and minimizes processingdelay.

One feature of the present invention is the capability to selectivelyassociate on-the-fly both command and feedback paths between the masterand slave manipulators. For example, the exclusive operationmaster/slave association shown in FIG. 5 may be altered on-the-fly(i.e., during a minimally invasive surgical procedure rather than atset-up) to the bilateral master/slave association shown in FIG. 9 byre-associating the command path of the master 501 from the slave 502 tothe slave 512 while maintaining the feedback path of the slave 502 tothe master 501, re-associating the command path of the master 511 fromthe slave 512 to the slave 502 while maintaining the feedback path ofthe slave 512 to the master 511, providing a value indicating the inputforce applied against the master 501 to the master 511, and providing avalue indicating the input force applied against the master 511 to themaster 501.

FIG. 11 illustrates an example of input/output ports for the associationmodule 1001, in which input ports A˜F are shown on the left side of theassociation module 1001 for convenience, and output ports U˜Z are shownon the right side of the association module 1001 for convenience.

Input port A is assigned to the output of the master processing 420which is provided on line 1014 of FIG. 10, input port B is assigned tothe surgeon force input to the master manipulator 404 which is providedon line 1042 of FIG. 10, input port C is assigned to surgeon force inputto the master manipulator 1004 which is provided on line 1052 of FIG.10, input port D is assigned to the output of the master processing 1020which is provided on line 1054 of FIG. 10, input port E is assigned tothe output of the slave processing 430 which is provided on line 1035 ofFIG. 10, and input port F is assigned to output of the slave processing1030 which is provided on line 1075 of FIG. 10.

Output port U is assigned to the input to the slave processing 430 whichis provided on line 1024 of FIG. 10, output port V is assigned to theinput force to the master manipulator 1004 which is provided on line1053 of FIG. 10, output port W is assigned to the input force to themaster manipulator 404 which is provided on line 1042 of FIG. 10, outputport X is assigned to the input to the slave processing 1030 which isprovided on line 1064 of FIG. 10, output port Y is assigned to thefeedback to the master processing 420 which is provided on line 1045 ofFIG. 10, and output port Z is assigned to the feedback to the masterprocessing 1020 which is provided on line 1085 of FIG. 10.

FIG. 12 illustrates a routing table corresponding to the master/slaveassociation shown in FIG. 9, and FIG. 13 illustrates a routing tablecorresponding to the master/slave association shown in FIG. 8. Referringto FIG. 12, input port A is connected to output port X (i.e., line 1014is coupled to line 1064 of FIG. 10, which corresponds to line 903 ofFIG. 9), input port B is coupled to output port V (i.e., line 1042 iscoupled to line 1053 of FIG. 10, which corresponds to line 921 of FIG.9), input port C is connected to output port W (i.e., line 1052 iscoupled to line 1043 of FIG. 10, which corresponds to line 922 in FIG.9), input port D is connected to output port U (i.e., line 1054 iscoupled to line 1024 of FIG. 10, which corresponds to line 913 in FIG.9), input port E is connected to output port Y (i.e., line 1035 iscoupled to line 1045 of FIG. 10, which corresponds to line 904 in FIG.9), and input port F is connected to output port Z (i.e., line 1075 iscoupled to line 1083 of FIG. 10, which corresponds to line 914 in FIG.9).

If the Mentor Surgeon (M) is operating the master 901 and desires atthis point to change the master/slave association from that of FIG. 9 tothat of FIG. 8, he/she provides appropriate switch command(s) 1005 by,for example, depressing a button on his/her right-hand master inputdevice corresponding to the master 901 so that the command output of themaster 901 is provided to the slave 902 instead of the slave 912, andselecting menu entries on his/her display to stop providing commands toor receiving force feedback from the slave 912, to provide the forcefeedback from the slave 902 to the master 911 (as well as continuing todo so to the master 901), and stop providing the input force exerted onthe master input device of the master 911 to the master 901.Alternatively, as previously described, these switches may be done usingfoot pedals, voice actuation, or any combination of buttons, footpedals, voice, display menu, or other actuation devices controllable bythe Mentor Surgeon (M).

FIG. 13 illustrates the routing table resulting from the above describedswitch command(s) 1005 that places the master/slave association into theconfiguration shown in FIG. 8. In this case, input port A is connectedto output port U (i.e., line 1014 is coupled to line 1024 of FIG. 10,which corresponds to line 803 of FIG. 8), input port B is coupled tooutput port V (i.e., line 1042 is coupled to line 1053 of FIG. 10, whichcorresponds to line 821 of FIG. 8), input port C is not connected to anyoutput port, input port D is connected to output port U (i.e., line 1054is coupled to line 1024 of FIG. 10, which corresponds to line 813 inFIG. 8), input port E is connected to output ports Y and Z (i.e., line1035 is coupled to line 1045 and 1085 of FIG. 10, which corresponds toline 804 in FIG. 8), and input port F is not connected to any outputport.

Referring back to FIG. 8 now, it is noted that the slave 802 has twocommand inputs, one from the master 801 and another from the master 811.This causes a control contention issue which may be resolved by theshared command filter 1002 of the association module 1001 of FIG. 10.

FIGS. 14 and 15 illustrate block diagrams for alternative embodiments ofthe shared command filter 1002. As shown in FIG. 14, the shared commandfilter 1002 takes the form of a simple arbiter, selecting either a firstcommand input CMD1 or a second command input CMD2, depending upon apriority input which is provided as a switch command 1005 to theassociation module 1001 by the Mentor Surgeon (M) or programmed into orprovided as a parameter value for its process code. As shown in FIG. 15,the shared command filter 1002 may also take the form of a weighter orweighting function that weights command inputs CMD1 and CMD2, andcombines the weighted values to determine a shared command value to beprovided to the slave. In this case, the respective weights of the firstand second command inputs, CMD1 and CMD2, depend on a weight input whichis provided as a switch command 1005 to the association module 1001 bythe Mentor Surgeon (M), or programmed into or provided as parametervalues for its process code.

In the foregoing description of the switching process from onemaster/slave association to another, it has been assumed that suchswitching occurs instantaneously. However, to avoid undesirabletransient movement of the slave robotic mechanisms, it may be desirablein certain circumstances to phase-in the switching process (i.e.,gradually reducing the strength of the signal being switched out whilegradually increasing the strength of the signal being switched in), orusing a clutch mechanism that disengages both signals and only engagesthe new signal, for example, after making sure that the position of theslave robotic mechanism being commanded by the new signal matches thatof the old signal so that a sudden movement will not occur as a resultof the change.

Although the various aspects of the present invention have beendescribed with respect to a preferred embodiment, it will be understoodthat the invention is entitled to full protection within the full scopeof the appended claims.

What is claimed is:
 1. A medical system comprising: a first slavemanipulator configured to move a first device according to a first slavecommand; a first input device operated by a first user, the first inputdevice configured to generate a first command by the first useroperating the first input device; and a control station operated by asecond user, the control station coupled to the first slave manipulatorand the first input device, the control station including: a secondinput device operated by the second user, the second input deviceconfigured to generate a second command by the second user operating thesecond input device; means for generating one or more switch commands;and an association module adapted to: receive the first command and thesecond command, generate the first slave command by using one or both ofthe first command and the second command according to the one or moreswitch commands; and provide the first slave command to the first slavemanipulator.
 2. The medical system according to claim 1, wherein theassociation module comprises: a plurality of inputs, a first inputassociated with the first input device to receive the first command, asecond input associated with the second input device to receive thesecond command; a plurality of outputs, a first output associated withthe first slave manipulator; a routing table selectively coupling theplurality of inputs to the plurality of outputs according to the one ormore switch commands; and a shared command filter; wherein theassociation module is configured to: conditioned upon the routing tableselectively coupling only one of the first command and the secondcommand to the first output, generate the first slave command by usingthe selectively coupled one of the first command and the second command;and conditioned upon the routing table selectively coupling both of thefirst command and the second command to the first output, coupling thefirst command and the second command to the shared command filter togenerate the first slave command according to the one or more switchcommands.
 3. The medical system according to claim 2, wherein the sharedcommand filter comprises: an arbiter configured to select one of thefirst command and the second command to be the first slave command,according to a priority input included among the one or more switchcommands.
 4. The medical system according to claim 2, wherein the sharedcommand filter comprises: a weighting function configured to weight eachof the first command and the second command to generate the first slavecommand, according to weight values, included among the one or moreswitch commands, for the first input device and the second input device.5. The medical system according to claim 1, wherein the means forgenerating one or more switch commands comprises: means for phasing-in anew switch command and phasing-out an old switch command when selectivecoupling of the plurality of inputs to the plurality of outputs by therouting table is to change as a result of the old switch command beingreplaced with the new switch command.
 6. The medical system according toclaim 1, wherein the means for generating one or more switch commandscomprises any one or a combination of: one or more buttons on the secondinput device, one or more foot pedals, a voice recognition andprocessing system, a graphical user interface, and other user operableinput mechanism.